Image display

• US 10,416,480 B2
• Filed: 01/19/2016
• Issued: 09/17/2019
• Est. Priority Date: 03/13/2002
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Whitehead, Lorne A., Ward, Gregory John, Stuerzlinger, Wolfgang, Seetzen, Helge, Graham, Don
• Primary Examiner(s): Dinh, Jack
• Application Number:
  US15/001,068
• Publication Number:
  US 20160170236A1
• Time in Patent Office: 1,337 Days
• Field of Search: 359238
• CPC Class Codes: G02F 1/133524 Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133613 characterized by the sequence of light sources
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2330/08 Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/3426 : the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/3611 : Control of matrices with row and column drivers
• CPC Class Codes: H01J 63/06 : Lamps with luminescent screen excited by the ray or stream
• CPC Class Codes: H04N 9/3102 : using two-dimensional electronic spatial light modulators micromechanical modulators as such G02B26/0833; liquid crystal modulators as such G02F1/13
• CPC Class Codes: H04N 9/3126 : for spatial light modulators in series
• CPC Class Codes: H04N 9/3155 : for controlling the light source light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406
• CPC Class Codes: H04N 9/3194 : including sensor feedback
• CPC Class Codes: H04N 9/3197 : using light modulating optical valves
• CPC Class Codes: H05B 45/20 : Controlling the colour of the light

Abstract

A display has a screen which incorporates a light modulator. The screen may be a front projection screen or a rear-projection screen. The screen is illuminated with light from a light source comprising an array of controllable light-emitters. The controllable-emitters and elements of the light modulator may be controlled to adjust the intensity of light emanating from corresponding areas on the screen. The display may provide a high dynamic range.

Claims

1. A display comprising:

a light source comprising an array of light-emitting elements each having a controllable light output;

a spatial light modulator illuminated by-the light source; and

a grid of reflective-walled channels disposed between the light source and the spatial light modulator;

wherein light from the light source passes through the channels to illuminate the spatial light modulator.

2. A display according to claim 1 wherein the array of light-emitting elements comprises a rectangular array.

3. A display according to claim 1 wherein the grid comprises a honeycomb structure.

4. A display according to claim 3 wherein the honeycomb structure comprises an aluminium honeycomb material.

5. A display according to claim 3 wherein the light-emitting elements are arranged in a hexagonal array.

6. A display according to claim 1 wherein reflective walls of the channels provide an interface at which light is totally internally reflected.

7. A display according to claim 1 wherein the grid is spaced away from the spatial light modulator.

8. A display according to claim 1 wherein the channels have a length L which satisfies

9. A display according to claim 1 wherein the light-emitting elements emit white light.

10. A display according to claim 1 wherein the light-emitting elements comprise light-emitting diodes.

11. A display according to claim 10 wherein the grid is provided by columns formed integrally with material that encapsulates the LEDs.

12. A display according to claim 1 wherein one of the channels is provided for each of the light-emitting elements.

13. A display according to claim 1 wherein, for each of the channels, the light source comprises a plurality of LEDs.

14. A display according to claim 13 wherein the LEDs for each of the channels emit light of a plurality of different colours.

15. A display according to claim 13 wherein LEDs operative to emit a mix of red, green, and blue light correspond to each of the channels.

16. A display according to claim 1 wherein the grid functions to improve uniformity of illumination of that part of the spatial light modulator illuminated by each of the light-emitting elements.

17. A display according to claim 1 wherein the channels are hexagonal in cross-section.

18. A display according to claim 1 wherein the channels are triangular or square in cross-section.

19. A display according to claim 1 comprising a controller connected to control the light-emitting elements of the light source to provide a low-resolution version of an image to be displayed on the spatial light modulator.

20. A display according to claim 1 wherein the spatial light modulator is a high-resolution colour light modulator.

21. A display according to claim 1 wherein the display has a thickness of 10 cm or less.

22. A display according to claim 1 wherein the reflective-walled channels comprise columns of light-transmitting material having walls at which light is internally reflected.

23. A display according to claim 22 wherein the columns are integral with the light-emitting elements.